Relational DataBase Management Systems (RDBMS) now play a major role in e-business. Vast quantities of business data are gathered, stored and processed, which demands more powerful support from backend RDBMS servers. However, current RDBMS systems do not support true and secure data encryption.
There are several database products that support weak data encryption, all of which use loose coupling. That is, data are first encrypted outside the database engine and then loaded into the database. Consequently, the stored encrypted data cannot be processed efficiently by the database engine itself, losing the advantage of using an RDBMS to manage the data in the first place.
The major problem with the loose coupling approach is that encrypted data is dead data (from a query processing point of view) inside the database and is resurrected to life only after it is fetched back out and decrypted. This makes query processing almost impossible, and efficient database techniques such as indexes cannot be used at all.
Another problem with current RDBMS is that some users have too much power to access any data. For example, a system administrator or a database administrator can access and modify data that are owned by other people without any restriction.
What is needed is a system that integrate encryption and decryption with the relational database so that one may have both the benefits of encryption and all the benefits of a relational database.